A coalition of healthcare provider associations says many common practices are costly, often unnecessary and sometimes even harmful.

WASHINGTON — Nearly 100 medical procedures, tests and therapies are overused and often unnecessary, a coalition of leading medical societies says in a new report aimed at improving healthcare and controlling runaway costs.

The medical interventions — including early caesarean deliveries, CT scans for head injuries in children and annual Pap tests for middle-aged women — may be necessary in some cases, the physician groups said. But often they are not beneficial and may even cause harm.

"We are very concerned about the rapidly escalating cost of healthcare," said Dr. Bruce Sigsbee, president of the American Academy of Neurology, which was among the 17 medical groups contributing to the list of procedures. "This is not healthy for the country, and something has to be done."

Development of the list, which was organized by the American Board of Internal Medicine's ABIM Foundation, is a minor milestone in efforts to enlist physicians to rein in unnecessary services, a leading cause of the skyrocketing healthcare tab.

In 2011, the ABIM Foundation published a similar list of procedures submitted by nine other medical societies as part of its Choosing Wisely campaign.

The United States spends more than $2.5 trillion a year on healthcare, or more than $8,000 per person. That is 21/2 times as much as the average spent by other industrialized nations, according to data collected by the Organization for Economic Cooperation and Development, whose members include the richest nations.

Studies show that the high cost of U.S. healthcare is driven in large part by prices. American hospitals and doctors charge much more than their international counterparts.

But U.S. physicians also perform many more tests and elective procedures. For example, American doctors order nearly twice as many CT and MRI exams as doctors in other industrialized countries do. They perform more knee replacements and deliver more babies by caesarean section.

Some of this extra care may result in better outcomes. The U.S. has some of the highest cancer survival rates in the world, for instance.

But America lags far behind other industrialized countries in caring for children with asthma and adults with chronic bronchitis and emphysema, among other illnesses.

A growing number of experts have concluded that much medical care in the U.S. is wasteful and even dangerous for patients. A 2012 report from the independent Institute of Medicine estimated total waste in the system at 30%, or $750 billion a year.

"Millions of Americans are increasingly realizing that when it comes to healthcare, more is not necessarily better," said Dr. Christine K. Cassel, president of the ABIM Foundation.

For example, despite the popularity of early caesareans, there is growing evidence that babies born before 39 weeks' gestation have higher risks of learning disabilities and even death.

Whether, or how quickly, the initiative to curb unnecessary procedures will yield results remains unclear.

Persuading doctors to be more conservative can be difficult, said Dr. Lowell E. Schnipper, an oncologist at Boston's Beth Israel Deaconess Medical Center and chairman of a national task force on controlling the cost of cancer care. "These diseases can be fatal," Schnipper said. "The stakes are high. And families very often push the doctor, who wants to take care of the patient as best he or she can."

Recent warnings from the U.S. Preventive Services Task Force that screenings for breast and prostate cancers often do more harm than good drew huge backlashes from patient advocates. Similarly, the Obama administration's efforts to raise awareness about unnecessary medical care and to improve data on best medical practices as part of the 2010 healthcare law prompted many Republicans to characterize the ideas as rationing.

But Dr. Manoj Jain, a leading health quality advocate in Memphis, Tenn., said more aggressive efforts may be needed to reduce wasteful and dangerous medical practices.

Like many experts, Jain advocates more evaluation of physicians and new ways to pay for healthcare that reward better outcomes and higher efficiency instead of the current fee-for-service system, which pays doctors for every procedure they do.

"If we really are going to bend the cost curve, we have to get really serious," Jain said.

Among the medical societies that identified overused procedures prescribed by their members were the American Academy of Pediatrics, the American Academy of Ophthalmology, the American College of Obstetricians and Gynecologists, and the Society of Thoracic Surgeons.

The ABIM Foundation effort also drew support from leading consumer and business groups, including Consumer Reports, the AARP and the National Business Group on Health.